The navbar have currently no purpose.

The "Navigation" link does nothing.

Furthermore on Account Management there is no navbar at all.

I believe Hylke introduced navbar to keep visual consistency,
https://github.com/aerogear/aerogear-unifiedpush-server/commit/dbc9400bba97647260a72974dbe5b4f58c0e8e06

but I don't personally see any reason why it should be kept there.